Investigations into what caused two Boeing 737 Max 8 flights to crash in similar ways less than six months apart are still ongoing. Inspections found that both ill-fated aircraft were missing safety features that could have helped the pilots identify the source of erratic speed and altitude changes. These safety features were optional, and Boeing charged extra for them. Both Lion Air and Ethiopian Airlines opted not to make the purchase.
The two components are centered around an aircraft sensor, called the angle of attack (or AOA) sensor. The AOA sensor measures the angle of the aircraft’s nose, as well as the angle at which air passes over the wings. On the Max series, there is a computer system, called a Maneuvering Characteristics Augmentation System (MCAS) that automatically pushed the jet’s nose downward if the AOA sensor said it was too high, which puts the aircraft at risk of an aerodynamic stall.
One of the components in question is called an angle of attack indicator, which displays AOA information in the cockpit. The other, called a disagree light, is triggered when the two readings from the AOA sensors don’t match. The Federal Aviation Administration (FAA) never made either feature mandatory.
- Southwest Airlines installed the AOA indicators in all of their Max cockpits after the first crash by Lion Air.
- American Airlines purchased both the AOA indicator and the disagree light for all 737 planes upfront.
- United Airlines did not purchase either of the optional components, saying its pilots use other data to safely operate the aircraft.
Boeing plans to make at least the disagree light a standard feature on its Max aircraft. Boeing is also set to rollout a software update to the MCAS program soon. All 737 Max aircraft are grounded, at least until the software update is complete. Boeing said in a previous statement that it supported the decision to ground the planes “out of an abundance of caution.”
FAA Faces Questions about Boeing at Two Hearings
Transportation officials vowed to make changes to the Federal Aviation Administration’s (FAA) oversight process as the department tries to handle the repercussions of the two fatal crashes.
During public hearings, two Senate subcommittees raised concerns about the safety certification process and the decision making that surrounded the aircraft, which marked the first time leaders of the Department of Transportation and FAA have testified over their handling of the Boeing 737 Max aircraft.
In an effort to improve the oversight and certification processes, inspector general Calvin Scovel told the Senate Subcommittee on Aviation and Space that a revised version of the Organization Designation Authorization (ODA) program will be introduced by the FAA this summer. The program allows plane manufacturers to self-certify some aspects of airplane development. The updated oversight process will develop new criteria for evaluating companies’ training and self-audit procedures.